Hearing aid wireless network

ABSTRACT

A hearing aid includes a transceiver for interconnection of the hearing aid with a wireless network, and a communication controller that is adapted for controlling data exchange through the network in accordance with a network protocol, wherein the controller is further adapted for initialisation of the network in an acquisition mode by controlling the transceiver to transmit interrogation data repetitively, and upon receipt of an interrogation data received message from another device, in a connected mode acting as a master of the network by repetitively transmitting synchronization data at intervals that are longer than the intervals between transmitted interrogation data in the acquisition mode.

The present invention relates to a hearing aid wireless network forwireless interconnection of hearing aids, and wireless interconnectionof hearing aids with other devices, such as a remote control for ahearing aid, a fitting instrument, a mobile phone, a headset, a doorbell, an alarm system, a broadcast system, e.g. replacing a tele coilsystem, etc, etc.

WO 01/54458 discloses a method and a system for fitting, programming, orupgrading a hearing aid system. One system includes the use of a mobiledevice to interact with the hearing aid system through a short-rangenetwork. The short-range network is a pico-cellular network includingBluetooth technology. It is suggested to use Bluetooth to interconnectthe hearing aid with cellular phones, audio headsets, computer laptops,personal digital assistants, digital cameras, etc. Other radio networksare suggested, namely HomeRF, DECT, PHS, or Wireless LAN (WLAN).

However, the suggested conventional communication protocols require alarge amount of code for their implementation. For example, theBluetooth protocol requires 80-100 Kbytes code. Further, the powerconsumption during execution of the protocols is significant renderingthe bluetooth protocol impractical in a hearing aid.

Thus, there is a need for a wireless network with a communicationprotocol that is simple thereby requiring a small amount of code andwith low power consumption during operation. Further, the acquisitiontime should be low, and the latency should be low.

In accordance with a first aspect of the invention, the above and otherobjects are fulfilled by provision of a hearing aid comprising atransceiver for interconnection of the hearing aid with a wirelessnetwork for communication with a plurality of other devices, and acommunication controller that is adapted for controlling data exchangethrough the network in accordance with a simple network protocol.

The hearing aid wireless network according to the invention facilitatesinterconnection of a plurality of devices in the network, such ashearing aids, remote controllers, fitting instruments, mobile phones,headsets, door bells, alarm systems, broadcast systems, such as telecoil replacement, etc, etc.

Typically, in the hearing aid transceiver, transmission requires lesspower than reception. Therefore, the protocol according to the presentinvention seeks to minimize the time used for reception of data, e.g.during acquisition.

Acquisition is the process of initially establishing a network and theprocess of a new device establishing connection with an existingnetwork.

In an established network, the master device, in a connected mode,regularly transmits synchronization data, e.g. comprised in a linkmanagement package, for synchronization of the slave devices in thenetwork with the master device. During initialisation of the network,for example upon turn-on of two hearing aids, each device in anacquisition mode transmits interrogation data, e.g. comprised in a linkmanagement package, at a higher rate than the rate of transmission ofthe synchronization data in the connected mode.

The acquisition method according to the present invention has low powerconsumption during execution and it is fast.

Thus, it is an important advantage of the present invention that ahearing aid may connect with the network with a low power consumptionadequately supplied by, e.g., conventional ZnO₂ batteries, and that theprotocol may be implemented in the hearing aid with a low number ofinstructions, such as app. 1000 instructions. Further, it has a lowacquisition time, at least during initialisation of the network.

The transceiver and communication controller may operate according to afrequency division multiplex scheme (FDM) wherein the frequency rangeutilized by the network is divided into frequency channels, anddifferent devices in the network communicate in specific respectivefrequency channels.

Alternatively, the transceiver and communication controller may operateaccording to a time division multiplex scheme (TDM) wherein the time isdivided into numbered time slots and different devices in the networkcommunicate in specific respective time slots.

The transceiver and communication controller may also operate accordingto a combined FDM and TDM scheme.

Preferably, the transceiver and communication controller operatesaccording to a frequency diversification or spread spectrum scheme, i.e.the frequency range utilized by the network is divided into a number offrequency channels, and transmissions switch channels according to apredetermined scheme so that transmissions are distributed over thefrequency range. According to the present invention, a frequency hoppingalgorithm is provided that allows devices in the network to calculatewhat frequency channel the network will use at any given point in timewithout relying on the history of the network, e.g. based on the presentfrequency channel number, a pseudo-random number generator calculatesthe next frequency channel number. This facilitates synchronization of anew device in the network, e.g. the new device comprises the samepseudo-random number generator as the devices already connected in thenetwork. Thus, upon receipt of the current frequency channel numberduring acquisition, the new device will calculate the same nextfrequency channel number as the other devices in the network.

Preferably, one device in the network is a master device. All otherdevices in the system synchronize to the timing of the master device,and preferably, the master device is a hearing aid, since the hearingaid user will always carry the hearing aid when he or she uses thenetwork.

Every device in the network has its own identification number, e.g. a32-bit number. Globally unique identities are not required since theprobability of two users having hearing instruments with identicalidentifications is negligible.

Preferably, a new device is automatically recognized by the network andinterconnected with the network.

It is an advantage of a network operating according to a spread spectrumscheme that the communication has a low sensitivity to noise, sincenoise is typically present in specific frequency channels, andcommunication will only be performed in a specific channel for a shorttime period after which communication is switched to another channel.

Further, several networks may co-exist in close proximity, for exampletwo or more hearing aid users may be present in the same room withoutnetwork interference, since the probability of two networkssimultaneously using a specific frequency channel will be very low.

Likewise, the hearing aid network may coexist with other wirelessnetworks utilizing the same frequency band, such as Bluetooth networksor other wireless local area networks.

In accordance with a second aspect of the invention, hearing aidsaccording to the present invention may advantageously be incorporatedinto a binaural hearing aid system, wherein two hearing aids areinterconnected through the wireless network for digital exchange ofdata, such as audio signals, signal processing parameters, control data,such as identification of signal processing programs, etc, etc, andoptionally interconnected with other devices, such as a remote control,etc.

Devices remotely located in relation to the devices in the network maydesirably provide signals to a hearing aid or another device in thewireless network. Such a remotely located device may be a doorbell, analarm clock, a broadcasting system, etc. In their remote locations, suchdevices may not receive synchronization information transmitted by themaster of the network and thus, may not be able to synchronize to thenetwork. On the other hand, typically, such devices are not subject topower limitations, and therefore such devices are adapted to, inaccordance with the present invention, transmit information during along time period in one or more predetermined frequency channels therebyenabling reception of the information by the intended device in thenetwork.

In the following, the invention will be further explained with referenceto the drawing wherein:

FIG. 1 schematically illustrates a hearing aid according to the presentinvention coupled to a wireless network,

FIG. 2 illustrates slots and frames,

FIG. 3 illustrates slot timing,

FIG. 4 illustrates common transmission/reception processing,

FIG. 5 illustrates data transmission processing and package assembling,

FIG. 6 illustrates data reception processing,

FIG. 7 illustrates data exchange of an initial acquisition process,

FIG. 8 illustrates data exchange during a hearing aid acquisitionprocess,

FIG. 9 illustrates data exchange during a connection negotiationprocess,

FIG. 10 illustrates the timing of a hearing aid acquisition process,

FIG. 11 illustrates in more detail two of the frames of FIG. 10,

FIG. 12 illustrates details of communication of LMPs of FIG. 10,

FIG. 13 illustrates a half frame slave reception, and

FIG. 14 is a blocked schematic of a transceiver and communicationcontroller according to the invention.

FIG. 1 schematically illustrates a binaural hearing aid with a left earhearing aid and a right ear hearing aid, each of which has a transceiverand communication controller for connection with a wireless networkinterconnecting the two hearing aids, and interconnecting the hearingaids and a plurality of other devices in the wireless network. In theexample illustrated in FIG. 1, a doorbell, a mobile phone, a cordlessphone, a TV-set, and a fitting instrument are also connected to thewireless network.

A network is a means of interconnecting a set of devices forcommunication of data between the devices. According to the presentinvention, one of the devices in the network act as a master device,i.e. it transmits timing information to the other devices in the networkfor synchronization. Thus, the master device controls the timing of thedevices. The other devices are slave devices.

An ID identifies every device. The ID is unique within the network.

The illustrated embodiment of the invention operates in the 2.4 GHzindustrial scientific medical (ISM) band. It comprises 80 frequencychannels of 1 MHz bandwidth. A frequency hopping TDM scheme is utilized.

During acquisition, the frequency hopping scheme comprises a reducednumber of frequency channels, e.g. less than 16 channels, preferably 8channels, for faster acquisition. Members of the reduced set offrequency channels are denoted acquisition channels. Preferably, theacquisition channels are distributed uniformly throughout the frequencyband utilised by the network.

According to the protocol and as shown in FIG. 2, the time is dividedinto so-called slots that have a length of 1250 μs (twice the length ofa minimum Bluetooth™ slot). The slots are numbered from 0 to 255.

256 slots, i.e. slot 0 to slot 255, constitute a frame. Frames are alsonumbered.

Among factors influencing selection of the length of a slot, is therequired lower latency of the system and a desired low overhead withrespects to headers and PLL locking. Preferably, the slot length is amultiple of 625 μS, facilitating (i.e. not prevent) that the protocolaccording to the invention can be implemented on BLUETOOTH™ enableddevices.

Each slot (except slot 128) is used for transmission by one specificdevice so that data collisions inside the network are prevented. Anyslave device may transmit data in slot 128 and hence collisions mayoccur in this slot. The master device transmits timing information inslot 0. The master devices synchronise their timing circuits, e.g:counters, to the timing information received in slot 0. In oneembodiment, each device has a free running symbol, slot and framecounter. The slot and frame counters of a slave device are synchronizedwith the respective counters of the master device of the network.

A device may use one or more slots for transmission of data. Slots maybe allocated during manufacture of a given device, or, slots may beallocated dynamically during acquisition. Preferably, the allocationtable is stored in the master device.

The data structure of a slot is illustrated in FIG. 3. The basic devicefor sending data between devices in a network is a package. A packageconsists of a header, payload data, and CRC checksums. The CRC checksumonly allows determining, if a bit error has occurred (package integrity)eventual error correction may be implemented at a higher layer in theprotocol.

A SYNC word is used to detect the start of a package in a slot (or ifthere is a package). As is well known in the art, a SYNC-word isselected so that it has a low cross-correlation with SYNC-words used inother networks to avoid the possibility of confusioning SYNC-words fromdifferent networks. Further the SYNC-word must have a lowauto-correlation so that a complete overlap is required for a match tooccur whereby accurate timing is provided. In the illustratedembodiment, the SYNC-word is generated with a Gold code-generator.

All devices know a single SYNC word.

The duration of a symbol (1 bit) is 1 μs.

The performance of the present embodiment is: Lowest latency is 1.25 ms.The highest bandwidth is approximately 730 kb/s. The fastest responsetime is 2.5 ms. The response time is defined as the time fromtransmission of a request from a device until reception of a reply fromanother device.

During data communication, the frequency channel is changed for eachslot, hence 800 frequency hops are performed every second. The hoppingsequence is defined by a very long pseudo random sequence known by alldevices connected to the network. The sequence is a function of theidentification number (ID) of the master device, hence it allows severaldistinct networks to co-exist.

The bandwidth of the illustrated embodiment is 730 kb/s (using maximumsized data packages in every slot). The bandwidth can be optimised foreach application by selecting a number of slots that has the requiredaggregated bandwidth.

In FIG. 4, processing common for transmission and reception of data isillustrated. The frequency channel, synchronization word, and theframe/slot number to be utilized have to be determined.

The frame/slot counter is a 40-bit counter. The 8 least significant bitsconstitute the slot number (SLOT_CNT) and the 32 most significant bitsconstitute the frame number (FRAME_CNT). In the master device, theframe/slot counter is a free running counter. In a slave device, theframe/slot counter is synchronized to the slot 0 link managementpackage. The SYNC correlation timing performs this synchronization.Thus, the timing of the master device controls package timing, and allslaves synchronize to the master.

A pseudo random number generator generates the RF frequency-hoppingchannel (CHAN). The seeding value is based on:

-   -   The master identification number (MST_ID) so that different        networks (e.g. two sets of hearing aids in the same area) will        use different sequences to substantially eliminate interference        between different sets of hearing aids.    -   The slot number (SLOT_CNT) so that each slot utilizes a        different frequency channel.    -   The frame number (FRAME_CNT) so that a new sequence is utilized        in each frame, i.e. to avoid that slot 0 utilizes the same        frequency channel in every transmission.

The frequency channel number (CHAN) generation algorithm does notrequire storage of previous channel numbers, i.e. there is no memory inthe algorithm. The next channel number is calculated based on thecurrent channel number. The pseudo random sequence for thefrequency-hopping scheme and for generating the SYNC words isimplemented as a hardware block.

Package assembling and transmission processing is further illustrated inFIG. 5. The preamble and synchronization guard are fixed patterns. Thesynchronization word is either a copy of the two possible SYNC words(generated “once” by the SYNC word generation).

The rest of the package is generated by concatenation of the packageheader, the payload and the CRC of the payload. A seed using the CHANwhitens the package data. The whitening is necessary to suppress thedata DC.

Data reception processing is further illustrated in FIG. 6. The receiversearches for a package by correlation to the known SYNC word (MS_SYNC orLMP_SYNC). If the correlation succeeds, the bit timing and the positionin time of the first bit after the SYNC are known. The PREAMB andSYNCGUARD are ignored.

The header and payload fields are first de-whitened using the CHAN.

The different fields of the raw package are checked for errors.

The whitening algorithm is implemented in hardware and is implementedwith a linear feedback shift register (LFSR).

The Error checking algorithm protocol (at the base band level) does notimplement forward error correction. The only error checking performed ison the SLOTNUM and PKTLEN fields in the header, and using a CRC-16checksum on the data part of the payload. Additional error checking orcorrection of the data part may be implemented in the application layer.

The hearing aid acquisition process will now be described with referenceto FIGS. 7-13 showing timing diagrams of the initialisation of a networkby two hearing aids. In this example, the acquisition time is the timefor establishment of the new network.

An acquisition method that consumes little power and still is fast isprovided.

TABLE 1 Acquisition times Acquisition mode Time Description Initialacquisition 0 s-10.2 s (5.1 s average) When a new network isestablished, e.g. when two hearing instruments are powered on andestablish a network. Acquisition into existing network 0 s-82 s (41 saverage) When a network is already establish and a new device tries toconnect with the network High Power acquisition 0 s-2.56 s (1.28 saverage) Same as above, but this mode is VERY power consuming and cannotbe used with ZnO₂ batteries (but excellent for e.g. a remote control)

Acquisition is achieved when a device successfully receives a linkmanagement package in slot “0” and replies to it in slot “128”.

The acquisition process has the two conflicting requirements of fastacquisition time and low power consumption (which corresponds to lowtransceiver and communication controller activity). The acquisitionprocess according to the present invention saves power and stillprovides fast acquisition. Different devices may use differentacquisition processes in accordance with their power capacity. Forexample devices that are not subject to power limitations may use afaster acquisition process requiring more power.

As illustrated in FIG. 7, two hearing aids seeking to establish a newnetwork, both transmit LM NULL link management packages as interrogationdata. The hearing aid that first receives the LM NULL package from theother hearing aid turns into a slave in the network and synchronizes tothe other hearing aid using the timing information in the LM NULLpackage. Then the slave device transmits a LM REQ package in slot 128 tothe other hearing aid that turns into the master of the network andtransmits a LM REQ ACK in slot 0 whereby the network is established. Themaster device continues to transmit timing information in slot 0 forsynchronization of slave devices in the network.

FIG. 8 illustrates the acquisition process in more detail. In theillustrated embodiment, an acquisition cycle comprises 32 frames. In aselected half frame, the communication controller controls thetransceiver to enable reception of data at a selected acquisitionchannel. The position in the acquisition cycle of the half frameselected for reception may be determined by a pseudo-random numbergenerator to avoid synchronization with the other hearing aid. Further,the selected acquisition channel may be selected by anotherpseudo-random number generator for obtaining the advantages of thefrequency hopping scheme described above. In the other frames, Linkmanagement packages LMPs are transmitted with a high rate to increasethe speed of the acquisition. In the embodiment illustrated in FIG. 8,an LMP is transmitted in every 16 slot. Thus, 16 LMPs are transmittedwithin a frame.

Due to the frequency hopping of the transmission of the 16 LMPs in eachframe, all of the 8 acquisition channels are visited once within a halfframe. Thus, enabling reception of the transceiver during a half frameensures that the receiving device will receive one of the transmittedLMPs. No LMPs are transmitted within the frame preceding the receivinghalf frame so that the other hearing aid may respond to the previouslytransmitted LMPs.

According to the acquisition process, the first hearing aid receiving anLMP in the half frame turns into a slave in the network (in FIG. 8hearing aid HA 1 turns into the slave and hearing aid HA 2 turns intothe master).

In the event that a new device makes an acquisition to an existingnetwork, the above-mentioned acquisition cycle of 32 frames may berepeated until the new device receives an LMP from the master in theexisting network, or, an LMP from the new device “hits” slot 128 of themaster. Since the master is in the connected mode, it transmits only oneLMP per frame and thus, the probability of the new device receiving anLMP is reduced by a factor of 8 compared to the acquisition processdescribed above for network initialisation. In each acquisition cycle,the half frame for reception is positioned differently within the cycleso that some of the cycles will receive data in slot 0 of the master.

After reception of the LMP, the hearing aid enters into the connectionnegotiation process illustrated in FIG. 9.

The LM_NULL package received by the slave contains timing informationenabling the slave to be synchronized with the other hearing aid andthus, the slave can respond with an LMP in the, from now on, shared slot128, namely a LM_REGREQ package that notifies the slave to the master.The master responds with a LM_REGACK. From this point in time, the twodevices are connected. The master continues to transmit LMPs in slot 0for synchronization (and other purposes) of slaves in the network.

In the hearing aid acquisition process illustrated in FIGS. 7-9, bothhearing aids starts in the acquisition mode, i.e. initially they do notform part of a network.

FIG. 10 is a timing diagram illustrating the acquisition sequence of 32frames (ha1_frame_no: 0-31). FIGS. 11-13 illustrate various parts of thetiming diagram of FIG. 10 as indicated by the frame and slot numbers.The first hearing aid that performs the half frame reception willreceive an LMP. Thus, the maximum acquisition time is the 32-frame cycle(12.6 s), and the average acquisition time is about 6 s. The acquisitiontime ranges from 0 s to 12.5 s depending on the initial timingdifferences between the two hearing aids.

In an existing network, e.g., with a hearing aid acting as a masterdevice and, e.g., a remote control, the acquisition process is slower.If a second hearing aid is turned on, it powers up in an acquisitionmode, but the master hearing aid continues transmission of LMPs in slot0 at the normal rate.

Devices that have a larger battery/power capacity than a hearing aid,may use an acquisition process that receives continuously until an LMPis received.

Preferably, each device is capable of selectively acting as a masterdevice or a slave device in the network whereby a robust system isprovided. Further, a slave device is preferably capable of detectingpresence of the master device and capable of reacting to absence of amaster.

In a preferred embodiment, the slave devices change state and enter theacquisition mode when no Link management packages have been received inslot 0 for a predetermined period of time. If still no Link managementpackages are received, the slave devices start transmission of Linkmanagement packages in accordance with the network initialisationprocess described above.

For example, an existing network may comprise two hearing aids and aremote control device, the right hearing aid being the master device. Ifthe user turns the right hearing aid (master) off, the network loses itsmaster device, and the remaining devices must perform network recovery(which is no different from the initial network establishment) asdescribed above.

Since the transmission of data from the transceiver of the hearing aidaccording to the present invention requires little power, certaindevices that are located at a large distance from the master device(e.g. a doorbell) may not be able to pick up the link managementpackages from the master, and hence such devices may not connect to thenetwork. Devices in the network may receive data from such remotelylocated devices utilising a special protocol.

Typically, remotely located devices, such as a doorbell, a cooker timer,etc, do not rely on ZnO₂ batteries as a power source, and they arecapable of transmitting high power signals for long period of times.

In one embodiment, one or more slots and one or more frequency channelsare allocated for transmission of data from remotely located devices.

For example, when a doorbell rings it transmits multiple packages backto back for several seconds in accordance with the present invention.Devices in the network, such as a hearing aid that may use the data fromthe doorbell, listens on the allocated channels in allocated slots forthe transmitted signals.

In one embodiment, transceiver channels 9, 49 and 79 are allocated forsuch devices, and the remote devices transmit data for 4 seconds on eachof the three transceiver channels.

In a preferred embodiment, the hearing aid is adapted for manualselection of a master device of the network for reception of broadcastaudio signals, e.g. using remote control or buttons on the hearing aid.

For example, an auditorium may be equipped with a powerful transmitter(broadcast device), which broadcasts audio data. When a user enters theauditorium he/she may select to force the hearing aid(s) to use thebroadcasting device as a master. The broadcast device does not rely onreception of any data from the hearing instruments (uni-directionalcommunication).

FIG. 14 is a blocked schematic of a transceiver and communicationcontroller according to the invention. FIG. 14 also illustrates themajor data flow in ingress and egress.

In ingress, the RF chip interface 1 sends SPI commands to the RF chipfor configuration. The RF chip interface receives a data stream from theRF chip.

The correlator 2 extracts the slot and frame timing from the sync word,so that the rest of the receive chain can be synchronized. Based on thistiming, the header extraction block 3 analyses the package header andextracts the slot number and package length. Any errors in the headerare reported. The data de-whitening block 4 de-whitens the package data.The data is then converted to 16 bits parallel by the serial-parallelconversion block 5. The package data is stored in an internal databuffer 6 by the data buffer interface 7. The data is then accessible tothe DSP via the DSP interface 8 through the peripheral bus. A CRC checkcan also be performed on the package data 9. All internal configurationregisters and results of header checks, CRC errors etc are accessiblethough the DSP interface.

Slot and frame counters 10 are also provided as well as a number ofhardware timers 11.

The controller state machine 12 is responsible for overall timing of thebase-band engine.

A gold code generator 13 provides hardware assistance to the software inorder to generate gold codes used to program the sync words.

In egress, the RF chip interface 1 sends SPI commands to the RF chip forconfiguration.

The DSP writes a package of data to the data buffer 6, 7 via the DSPinterface 8. The package data has a CRC calculated via the data CRCgeneration block 9. The combined data payload and CRC are then convertedto serial 5 and whitened 4. The package header is constructed by theheader generation block 3 and then appended to the data. The completedpackage is then streamed to the RF chip by the RF chip interface 1.

While there have been described what are considered to be the preferredembodiments of this invention, it will be obvious to those skilled inthe art that various changes and modifications may be made thereinwithout departing from the invention.

1-34. (canceled)
 35. A method of initializing a wireless communicationnetwork comprising a hearing device including a wireless transceiver anda communication device comprising an other wireless transceiver, themethod comprising: transmitting interrogation data packets wirelessly bythe hearing device and the communication device, respectively; turningone of the hearing device and the communication device first receivingone of the interrogation data packets into a slave device in thewireless communication network; and transmitting a receptionacknowledgement data packet from the slave device indicating that theone of the interrogation data packets was received; turning the otherone of the hearing device and the communication device into a masterdevice in the wireless communication network upon receipt of thereception acknowledgement data packet from the slave device.
 36. Themethod according to claim 35, further comprising synchronizing the slavedevice to timing information data contained in the one of theinterrogation data packets received by the slave device.
 37. The methodaccording to claim 35, further comprising transmitting anacknowledgement data packet from the master device to the slave deviceindicating that the wireless communication network is established. 38.The method according to claim 35, wherein the reception acknowledgementdata packet is transmitted from the slave device in a timeslot allocatedfor reception acknowledgement data packet transmission.
 39. The methodaccording to claim 35, further comprising controlling each of thetransceivers in the wireless communication network to enable receptionof data packets at a predetermined acquisition channel.
 40. The methodaccording to claim 39, further comprising selecting the acquisitionchannel according to a frequency hopping scheme.
 41. The methodaccording to claim 35, further comprising transmitting an additionalinterrogation data packet by the master device in a timeslot allocatedto interrogation data packet transmission after the master device hasreceived the reception acknowledgement data packet from the slavedevice.
 42. The method according to claim 41, further comprising turningan additional communication device into an additional slave device whenthe additional communication device receives the additionalinterrogation data packet from the master device in the timeslotallocated to interrogation data packet transmission after the masterdevice has received the reception acknowledgement data packet from theslave device.
 43. The method according to claim 38, further comprisingturning an additional communication device into an additional slavedevice when the master device receives an additional interrogation datapacket from the additional communication device.
 44. The methodaccording to claim 35, further comprising transmitting an additionalinterrogation data packet by the slave device when the slave device doesnot receive any additional interrogation data packet from the masterdevice in a predetermined period of time.
 45. The method according toclaim 35, wherein at least one frequency channel is allocated fortransmission of data from remotely located devices with respect to thewireless communication network.
 46. A method of initializing a wirelesscommunication network comprising a hearing device including a wirelesstransceiver and a communication device comprising another wirelesstransceiver, the method comprising: transmitting interrogation datapackets wirelessly by the hearing device and the communication device,respectively; turning one of the hearing device and the communicationdevice first receiving one of the interrogation data packets into aslave device in the wireless communication network; and transmitting areception acknowledgement data packet from the slave device indicatingthat the one of the interrogation data packets was received.
 47. Themethod according to claim 46, further comprising synchronizing the slavedevice to timing information data contained in the one of theinterrogation data packets received by the slave device.
 48. The methodaccording to claim 46, further comprising transmitting a receptionacknowledgement data packet from the slave device in a timeslotallocated for reception acknowledgement data packet transmission. 49.The method according to claim 46, further comprising controlling each ofthe transceivers in the wireless communication network to enablereception of data packets at a predetermined acquisition channel.
 50. Ahearing device comprising: a wireless transceiver; and a digital signalprocessor communicatively coupled to the transceiver and configured totransmit a first interrogation data packet wirelessly via the wirelesstransceiver; wherein the digital signal processor is further configuredto turn the hearing device into a slave in a wireless communicationnetwork when the hearing device receives a second interrogation datapacket from another device in the wireless communication network. 51.The hearing device according to claim 50, wherein the digital signalprocessor is further configured to synchronize to timing informationdata contained in the second interrogation data packet received by thehearing device.
 52. The hearing device according to claim 50, whereinthe digital signal processor is further configured to transmit areception acknowledgement data packet in a timeslot allocated forreception acknowledgement data packet transmission.
 53. A hearing devicecomprising: a wireless transceiver; and a digital signal processorcommunicatively coupled to the transceiver and configured to transmit afirst interrogation data packet wirelessly via the wireless transceiver;wherein the digital signal processor is further configured to turn thehearing device into a master in a wireless communication network whenthe hearing device receives a reception acknowledgement data packet froma first communication device in the wireless communication networkbefore the hearing device receives a second interrogation data packetfrom the first communication device or another communication device inthe wireless communication network.
 54. The hearing device according toclaim 53, wherein the digital signal processor is further configured totransmit an acknowledgement data packet to the first communicationdevice from which the reception acknowledgement data packet is received,wherein the acknowledgement data packet is for indicating that thewireless communication network is established.
 55. The hearing deviceaccording to claim 53, wherein the digital signal processor is furtherconfigured to transmit an additional interrogation data packet in atimeslot allocated for transmitting the additional interrogation datapacket after the hearing device has received the receptionacknowledgement data packet.